Diagnostic Aids

If DTCs P0106 and P0121 are also set, ECT sensor ground circuit may be at fault. Ensure engine coolant level is full. Check for a faulty thermostat. Check for a shifted ECT sensor. See appropriate SENSOR OPERATING RANGE CHARTS article. A shifted sensor could result in poor driveability complaints.

An intermittent malfunction may be caused by a poor connection, rubbed-through wire insulation, or a wire broken inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, or poor terminal-to-wire connections before component replacement.